2. The different types of lights or lamps include the
following
• Incandescent lamps
• Halogen lamps
• Fluorescent tube
• Compact fluorescent lamps
• Light Emitting Diode
• Neon lamps
• High intensity discharge lamps
• Sodium vapour lamps
3.
4. Incandescent lamps
• Working: Lamp work on the principal
of Incandescence ( i.e. when a hot
body is heated, radiant energy is
emitted in waveform).
• An incandescent bulb generates light
through heat.(95% Heat,5% Light)
• The Incandescent light bulb produces
light by heating a metal filament wire
to a high temperature until it glows.
• The hot filament is protected from
oxidation in the air with a glass
enclose that is filled with inert gas or
evacuated
• Applications: Domestic, Commercial
and Industrial. Etc…
5. Halogen lamps
• A halogen lamp, also known as a tungsten
halogen, quartz-halogen or quartz iodine
lamp, is an incandescent lamp consisting
of a tungsten filament sealed into a
compact transparent envelope that is filled
with a mixture of an inert gas and a small
amount of a halogen such
as iodine or bromine.
• The combination of the halogen gas and
the tungsten filament produces a halogen
cycle chemical reaction which re deposits
evaporated tungsten to the filament,
increasing its life and maintaining the
clarity of the envelope.
• For this to happen, a halogen lamp must
be operated at a higher temperature (250°
C; 482º F)
6. Fluorescent tube
• A fluorescent lamp tube is filled with a gas
containing low pressure mercury vapor and
argon, xenon, neon, or krypton.
• The pressure inside the lamp is around 0.3% of
atmospheric pressure. The inner surface of the
lamp is coated with a fluorescent (and often
slightly phosphorescent) coating made of
varying blends of metallic and rare-earth
phosphor salts.
• The lamp's electrodes are typically made of
coiled tungsten and usually referred to as
cathodes because of their prime function of
emitting electrons. For this, they are coated
with a mixture of barium, strontium and
calcium oxides chosen to have a low
thermionic emission temperature.
7. Compact fluorescent lamps
• In addition, most compact
fluorescent lamps have an
"integral" ballast that is built
into the light bulb
• The primary difference is in
size; compact fluorescent
bulbs are made in special
shapes (which require
special technologies) to fit in
standard
household light sockets
8. Light Emitting Diode
• LEDs are semiconductor devices
that produces light when an
electrical current applied to them.
• Latest Lighting Technology.
Invented in 1962. Lower energy
consumption.
• Longer life : 50,000 – 100,000
Hrs.
• Smaller size , Faster switching.
9. Neon lamps
• And also called cold cathode
discharge lamps.
• These lamps Operates at a
very low temperature (200º
C)
• The electrodes are housed at
the two ends of the tube.
• Tube contains neon gas.
• Neon gas discharge gives a
characteristic red light
10. High intensity discharge lamps
• High-intensity discharge lamps (HID lamps)
are a type of electrical gas-discharge lamp
• which produces light by means of an electric
arc between tungsten electrodes housed
inside a translucent or transparent fused
quartz or fused alumina arc tube.
• This tube is filled with noble gas and often
also contains suitable metal or metal salts.
The noble gas enables the arc's initial strike.
Once the arc is started, it heats and
evaporates the metallic admixture. Its
presence in the arc plasma greatly increases
the intensity of visible light produced by the
arc for a given power input, as the metals
have many emission spectral lines in the
visible part of the spectrum.
11. Sodium vapour lamps
• A sodium-vapor lamp is a gas-discharge
lamp that uses sodium in an excited state to
produce light at a characteristic wavelength near
589 nm.
• Two varieties of such lamps exist:
• low pressure and high pressure. Low-pressure
sodium lamps are highly efficient electrical light
sources, but their yellow light restricts
applications to outdoor lighting, such as street
lamps.
• High-pressure sodium lamps emit a
broader spectrum of light than the low-pressure
lamps, but they still have poorer color
rendering than other types of lamps.
• Low-pressure sodium lamps only
give monochromatic yellow light and so inhibit
color vision at night.
